Heat-protective covering



J. H. WALSH.

HEAT BROTECTIVE COVERING; APPLlCATilON. EILED, JAN, 1s-a 191.9,

1 ,332, 3 1 4:, Patented Mar 2, 1920.

2 SHEETS-SHEET l.

J. H.. WALSH.

HEAT PROTECTIVE COVERING. APPLICATION. min JAN. 13, ms.

Patented Mar. .2, 1920.

2 SHEETS-SHEET 2- UNITED STATES PATENT orrron.

osnrn H. WALSH, or-nnnnm 'messecnusurrs, ASSIGNOR T 11. w. JOHNS- IMANVILLE COMPANY, A CORPORATION or NEW YORK.

HEAT-PROTECTIVE COVERING.

To all whom it may concern .1

Be it known that I, JOSEPH H. WALSH, a citizen of the United States of America, residing at, Reading, county of Middlesex,

State of Massachusetts, have invented certain new and useful Improvements in-Heat- Protective Coverings, of which thefollow ing is a specification.

My invention relates to the heat conduct ing arrangement of structures which are to besubjected to very high temperatures and has an important application'to the coverings of boiler blow-ofi? pipes. These blow-off pipes must usually passthrough the combustion chamber of the boiler furnace and are therefore constantly exposed to great heat. It has. been customary to equip them I with a covering of refractory and more or .difiiculty arising from these conflicting con 'ditions by inserting, in the non-conducting covering, segments or elements of conducting material, such as cast iron which are so shaped as to make a good heat-transferring contact with the pipe, and project outward to the exterior surface of the refractory covering. These conduct some of the heat from the covering to the blow-01f pipe, which conducts it to the boiler, which is at the much lower temperature of the contained boiling. water. Thus the temperatureof the covering is maintained below its fu's-' ing point, while the pipe is protected from.

direct action of the flame and gases. Preferably these conducting elements are separable from the pipe so that if they become badly burned or partly melted, they can be used for scrap and' new ones substituted at little expense, the refractory covering being atched to suit requirements of the replacing operation. I 2 The best form of apparatusembodying my invention at present known to me is illustrated in the accompanying two sheets of drawings in which,

Figure 1 is a vertical central section of a Specification of, Letters Patent.

Applicatioli' filed. January 13, 1919. Serial No. 270,834. I

covering 5. 'Various means ducting elements to the pipe maybe used.

' Patented Mar' 2,l1920.

portion of" a steam boiler and its setting illustratingthe blow-off pipeto which the invention is applied. Fig. 2 is an enlar ed side elevation and a partial section of said blow-0d pipe and its covering.

3 is a cross sectionon line 3-3 of Fig. 4 is a cross section on line 4-4 of Fig. 2.

scale of a modification, and v I Fig. dis a cross section on line 6-6 'of Fig.5. Throughout the drawings like reference characters indicate like parts.

' p Fig. 5'is a detail side view on an enlarged 1, is the boiler, 2 the'setting, and 3 the combustion chamber of the furnace formed under said boiler .by the setting. 4, is the usual blow-off pipe which, as it connects to the lowest point of the boiler, must extend through the combustion chamber ofithe fur-.

nace; 5, is the usual refractory and partially non-conductin covering for the pipe.

which preferably is ormed as shown in Fig.

2, where 5 is an asbestos rose wound about.

the pipe covered and embed ed in a plastic mass 5", such as a mixture of short asbestos fiber with any suitable heat resisting cement,-

the whole being incased in a tubular covering 5". The parts may be held in position .by a wire 12, wound around and'through them. To conduct a portion of theflgreat heat absorbed by the exterior of this covering away and so prevent the fusing point of the covering being reached, I employ elements of. heat conducting materials such as cast iron having are shaped portions 6, of a curvature such' as will enable them to fit snugly against the outer surface of the blow-off pipe, while from these arc-shaped portions extend radial portions 7 far enough to reach or pass beyond the surface of the refractory grooved, as shown. at l0,.to receive the fastening Wire 1]., by which one or more of the elements may be fastened snugly against the ipe in the position shown in the drawing.

1 referably the radial portions 7, are formed of two frustra ofcones having their axes in line and their-smaller ends 8, united. Theno outer cone then forms "a flaring head. This serves to retain the refractory coverin in position should it crack and tend to fal ofi' while the larger cross section of the inner cone as its base is approached afi'ords a better conductivity for the heat. These conducting elementsmay be made with one radial projection each, as shown'in Fig. 3, or with two or more as shown in Fig. 4. The

latter form is especially useful for att-ach-. D

ment to the pipe elbow, as shown-in Fig.2.

Another, and very convenient form of means for fastening the conducting elements to the pipe is provided byshaping them with interlocking projections and recesses as shown in Figs. 5 and 6, where each element, as 16, has an inward projection 14, and recess 13, forming a hook at one end of the are shaped section, and an outward recess 15, and projection 18, at the other end. When one such element, as-17, ,is slid over and under another, as 16,as indicated in Fig. 6, and in dotted lines in Fig. 5,-the

two elements interlock and are held in such interlocked position by reason of the pipe 4:, filling up the interior of the circle formed by any two assembled are shaped segments.

- By making the hooks formed by each set, of adjacent projections and depressions, as 1314, 1518-, point in the-same direction one toward the center of the arc, and the other outWard-this interlocking action is obtained between elements which are duplicates each of every other, so that only one pattern is needed for casting, and the necessity of carrying in stock an even number of two different types,-which would be the case if the'hooks pointed inward on one member and outward on the other,is

, avoided.

The advantages of the invention are the preservatlve action of the conducting elements in mechanically holding the refractory covering in place and in reducing its terial in direct contact therewith and a series of separate heat conducting elements adapted to be embedded in the refractory adapted to conduct a relatively cool fluid, a covering for said pipe of refractory material, indirect contact therewith and a series of separate heat conducting elements adapted to be embedded in the refractory covering with portions projecting at the exterior surface of the refractory covering, while other portions-of more extended area are adapted to rest against the pipe sur face and transmit heatthereto from the outer portions of the refractory covering, together with means for conveniently attaching said elements to, and detaching them from, the pipe. i i

3. A heat conducting element for use in preserving the refractory coverings for boiler blow-off pipes which consists of a mass of heat conducting material having a strip of small size relative to the mass of refractory covering shaped to an arc of a curvature corresponding to that of the eX- said element being so shaped that they willinterlock when a pair of such elements are assembled around the pipe.

4. A heat conducting element for use in preserving the refractory coverings for boiler blow-off pipes which consists of a mass of heat conducting material having a.

strip of small sizerelative to the mass of refractory covering shaped to an arc of a curvature corresponding to that of the exterior surfaces of the 1 e to which it is to be applied, and a radia ly projectin porit)io n, the arc-shaped portion of said e ement ein portins, one pointing. inward and the other outward to provide interlocking means when two elements are placed around the a pipe in proper position.

. @SEPH H. WALSH. Witnesses: An'rHt'na W. BANOROFT, R. A. Gasrnorin.

provided with similar hook-shaped.

65 ture comprising in. combination a pipe 

